Guitarra negra by Luis Alberto Spinetta is a collection of poetry in which the autor reminisces on his experience in the field of poetry and his role in Argentinian literature. In this article, some basic concepts of Spinetta’s poetry will be analyzed, in particular plant metaphors and mystic matter metaphors. Studying these concepts leads to the idea that revealing what is sacred is fundamental to Spinetta’s work. Wolfgang Janke’s concept of Post-ontology relates to Spinetta’s poetry, insofar as the way he dealt with ontolgy and postmodernism.